BHP Billiton has reaffirmed its full-year production guidance after achieving a 9 per cent lift in overall group production and record quarterly output of iron ore and metallurgical coal in the three months to the end of September.

In the three months to September 30, the miner produced 57.09 million tonnes of iron ore, a 17 per cent increase on the previous corresponding quarter.

The figure is ahead of a median estimate of analysts surveyed by Bloomberg at 56.5 million tonnes.

Total iron ore production is forecast to increase by 11 per cent in fiscal 2015 to 225 million tonnes, consistent with prior guidance.

Western Australia Iron Ore production increased by 15 per cent to a quarterly record of 62 million tonnes (100 per cent basis) as the ramp-up of Jimblebar continued ahead of schedule, BHP said.

Production of energy coal fell 9 per cent to 17.83 million tonnes, while metallurgical coal increased 25 per cent to a record 12.77 million tonnes.

Metallurgical coal is still forecast to increase by 4 per cent in fiscal 2015 to 47 million tonnes.

Total petroleum production was 67.4 million barrels of oil equivalent (mmboe), a 7 per cent lift on the previous corresponding period.

Full-year guidance for petroleum remains unchanged at at 255mmboe.

Copper output was 389,400 tonnes in the quarter, a 3 per cent slide on the previous corresponding quarter.

BHP Billiton chief executive Andrew Mackenzie said the miner remained on track to generate group production growth of 16 per cent over the two years to the end of the 2015 financial year.

"With our focus now on maximising the value of existing infrastructure, we plan to reduce costs and invest judiciously in very low capital cost de-bottlenecking initiatives," Mr Mackenzie said.

"These plans are expected to increase total supply chain capacity to 290 million tonnes per annum by the end of the 2017 financial year and reduce unit costs by at least 25 per cent to less than $US20 per tonne."

Mr Mackenzie said when combined with other initiatives across BHP's portfolio the group was well-positioned to reduce cash costs by more than $US2.3 billion and deliver volume-related productivity gains of at

least $US1.2bn by the end of the 2017 financial year.